Core C, the Clinical/Statistical Core, supports the three research projects and the technology development project (TDP). The Core has three units: the Hope Clinic Unit at Emory University, Atlanta, GA; the Dengue Clinical Unit at Siriraj Hospital, Bangkok, Thailand; and the Statistical Unit at Emory University, Atlanta, GA. Projects 1-3 are focused on advancing our fundamental understanding of immune memory, innate immunity, and immunological senescence. The TDP will develop novel technology for single cell analysis of the transcriptional and epigenetic landscape of immune cells. This Core will provide Projects 1-3, and the TDP, with human clinical specimens and statistical support for studies of yellow fever virus (YFV) vaccine and dengue virus infection. The clinical core has four specific alms: Aim 1) Provide expertise In conducting human research studies for successful completion of the CCHI scientific agenda. Core C activities Include: study design; clinical protocol and Informed consent document preparation and obtaining required regulatory approvals; recruitment of potential study participants; screening for eligibility, and enrollment; vaccinations; overall clinical study conduct according to Good Clinical Practice (GCP) standards; volunteer safety monitoring; clinical specimen collection, processing, and shipping; and preparation of progress reports, final reports, and publications. Aim 2) Perform YFV vaccine clinical studies. The Hope Clinic Unit at Emory University will design and conduct clinical studies with YFV vaccine In adults. Clinical specimens from these studies will be analyzed to accomplish the scientific alms of Projects 1, 2, and 3, and the TDP. Aim 3) Study immune responses in patients with dengue Infection. The Dengue Clinical Unit In Bangkok will design and conduct studies in hospitalized children and adults with dengue infection. Clinical specimens from this study will be analyzed to accomplish the scientific aims of Projects 1 and 2, and the TDP. Aim 4) Provide statistical and data management expertise that ensures the success of the CCHI scientific agenda. The biostatistics unit will ensure adequate study design, assist with data storage and sharing, analyze data to Its maximum potential, and develop statistical methods for the data analysis as necessary.